Why does using window mode result in such drastic performance penalties?

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Cali3350

Supreme [H]ardness
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Hey guys. I was recently bored and just decided to run a few quick Crysis tests.

Everything set to high 1280*1024
Fullscreen i get 38.5fps.
Windowed i get 26.5fps

What is it that causes this drop? Is it something to do with resizing the window after its been drawn or something like that? I prefer to play in windows (I'm weird) and always knew it hurt performance, but not that much!
 
i guess its becuase its not doing full screen rendering the card may still be in some kind of low power 3d mode?
 
In windowed mode, you also have to render the desktop and its apps as well, which draws away from the resources available to the game.
 
Mr. K6 said:
In windowed mode, you also have to render the desktop and its apps as well, which draws away from the resources available to the game.
Click to expand...

How much rendering power could rendering the desktop take away from the gpu? It's just a bunch of 2d icons.
 
Run task manager and see if memory usage differs when running the game windowed vs fullscreen
 
Skunt said:
How much rendering power could rendering the desktop take away from the gpu? It's just a bunch of 2d icons.
Click to expand...

AFAIK, just having a desktop background takes 20MB of memory to render...at least thats what my ex employer said...I have no way to confirm it - but he worked with NASA so I would take what he says for more than a grain on sand :p

Its always better to run a game in full screen and then minimize when needed - if it's possible for you.
 
Mr. K6 said:
In windowed mode, you also have to render the desktop and its apps as well, which draws away from the resources available to the game.
Click to expand...
Isn't the XP (and previous) desktops render in OGL, while most games are in DX? Could that have anything to do with it?
 
Its because cards are set to be in 3D mode only when you are using it in fullscreen - when your game is windowed your GPU frequency will be set to +- 2/3 of full speed.
 
FIDDYOWNZ said:
AFAIK, just having a desktop background takes 20MB of memory to render...at least thats what my ex employer said...I have no way to confirm it - but he worked with NASA so I would take what he says for more than a grain on sand :p

Its always better to run a game in full screen and then minimize when needed - if it's possible for you.
Click to expand...

So that extra graphics that the game would be displaying if it were in full-screen mode would be less than 20MB? I would have thought running the game in windowed mode would actually increase FPS but obviously it doesn't....reasonable ponder OP.
 
CaptNumbNutz said:
Isn't the XP (and previous) desktops render in OGL, while most games are in DX? Could that have anything to do with it?
Click to expand...

No. It isn't even using DirectDraw - there is no DX interaction from the desktop at all.

Vista does use DX for it's desktop, but XP and earlier do not have any 3d rendering capability there at all.
 
When using full screen i guess all priority goes to the program/game. When in window mode it probably treats it equally just like other windows like firefox or wordpad ;)
 
Im 100% sure its not a clock speed issue. Rivatuner confirms this (hardware mointoring open).
 
The clock speeds are the same, but as I said and conker also stated, it has to do with the priority of the processing. In windowed mode, the game gets treated as any other program because the rest of the windows desktop and other programs must also be rendered. This is not an optimal use of resources and so performance suffers. Windowed mode is helpful for development/tweaking, but not so much for getting your best bang for your buck performance.
 
Mr. K6 said:
In windowed mode, you also have to render the desktop and its apps as well, which draws away from the resources available to the game.
Click to expand...

So if i disabled my other monitor whilst playing a game and not looking at my desktop and vista sidebar id get better frames?
 
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